The MTC technique is a blanket term for a series of techniques implementing data communication and interaction among machines, as well as between a machine and a human being by applying wireless communication techniques, and combination thereof. The expression “Machine To Machine (M2M)” has two folds of meaning: the first being the machine itself, which is called a smart device in the embedded field; the second being the connection among machines, which connects the machines via a network, thereby making the human life more intelligent. MTC is widely applied, for example in smart measurement, remote monitoring and controlling, tracking, medical treatment and the like. Compared with traditional communications among people, MTC (M2M) devices are large in number, with a wide application field and enormous market prospect.
In the MTC, main long distance connection techniques include: Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), and Universal Mobile Telecommunications System (UMTS); short distance connection techniques mainly include 802.11b/g, Bluetooth, Zigbee, Radio Frequency Identification (RFID) and the like. As MTC integrates wireless communication and information techniques, it can be used for bidirectional communications, such as long distance information collection, parameter setting and instruction sending, and therefore can implement different application solutions, such as safety monitoring, automatic vending, cargo tracking and the like, with the possibility of almost all devices involved in daily life becoming potential service targets. The MTC provides simple means for device real time data to establish wireless connection among systems, remote devices, or individuals.
GBA refers to a Generic Bootstrapping Architecture, wherein the GBA hierarchy architecture defines a generic key negotiation mechanism between a UE and a server. FIG. 1 is a schematic diagram of the network model of the GBA hierarchy architecture; As shown in FIG. 1, the GBA network model mainly includes the following network elements:
UE (User Equipment): which is the blanket term for a terminal equipment (such as a mobile phone) and a (U) SIM card, and may be a mobile terminal equipment (such as a mobile phone and the like) with a plug-in card, or a fixed terminal equipment (such as a set-top box and the like) with a plug-in card;
NAF (Network Application Function): i.e., an application server, which implements an operation logic function of an application, and provides an operation service for the UE after completing authentication of the UE;
BSF (Bootstrapping Server Function): which is a core network element of the GBA, wherein the BSF implements authentication with the UE via an AKA protocol, and negotiates an application key which is used later on for the communications between the UE and the NAF, and the BSF can set a lifetime of the key according to a local strategy;
HSS (Home Subscriber System): i.e., a Home Subscriber Server, which stores authentication data in the (U) SIM card of the terminal, such as Ki in the SIM card and the like;
SLF: i.e., a Subscription Locator Function, wherein by inquiring from SLF, the BSF acquires the name of the HSS storing related user data. The SLF is not necessary in single HSS environment, nor required when the BSF is configured to use a preset HSS.
After introduction of the MTC device in the mobile communication system, the MTC device may need to communicate with a plurality of MTC servers. In the case where one MTC device communicates with one MTC server, the MTC device may establish a session key with the MTC server via a GBA process and establish a safe connection; However, when the MTC device needs to communicate with a plurality of MTC servers, it is necessary for the communication of the MTC device with a previous MTC server to complete before establishing the safe connection via the GBA process. This limits the ability of the MTC device to perform safe communications simultaneously with a plurality of MTC servers, and reduces the efficiency of network resources.